ALSA: vmaster - Free slave-links when freeing the master element

When freeing the vmaster master element, we should release slave-links
properly, not only assumig that slaves will be freed soon later.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 14 insertions, 4 deletions

diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 5dbab38d04af..130cfe677d60 100644
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -52,6 +52,7 @@ struct link_slave {
         struct link_ctl_info info;
         int vals[2];            /* current values */
         unsigned int flags;
+        struct snd_kcontrol *kctl; /* original kcontrol pointer */
         struct snd_kcontrol slave; /* the copy of original control entry */
 };
 
@@ -252,6 +253,7 @@ int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
                        slave->count * sizeof(*slave->vd), GFP_KERNEL);
         if (!srec)
                 return -ENOMEM;
+        srec->kctl = slave;
         srec->slave = *slave;
         memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
         srec->master = master_link;
@@ -333,10 +335,18 @@ static int master_put(struct snd_kcontrol *kcontrol,
 static void master_free(struct snd_kcontrol *kcontrol)
 {
         struct link_master *master = snd_kcontrol_chip(kcontrol);
-        struct link_slave *slave;
-
-        list_for_each_entry(slave, &master->slaves, list)
-                slave->master = NULL;
+        struct link_slave *slave, *n;
+
+        /* free all slave links and retore the original slave kctls */
+        list_for_each_entry_safe(slave, n, &master->slaves, list) {
+                struct snd_kcontrol *sctl = slave->kctl;
+                struct list_head olist = sctl->list;
+                memcpy(sctl, &slave->slave, sizeof(*sctl));
+                memcpy(sctl->vd, slave->slave.vd,
+                       sctl->count * sizeof(*sctl->vd));
+                sctl->list = olist; /* keep the current linked-list */
+                kfree(slave);
+        }
         kfree(master);
 }